The rise in community policing programs during the 1990s has led many local law enforcement agencies to regularly organize community events targeted at preventing crime, including the more than 3 million annual alcohol-related crimes that generate an estimated $84 billion in annual costs. Examples of such events include block parties, educational seminars, and police exhibitions. Although such police-led community events are widely viewed as an important component of a broader community policing strategy, little is known about how such activities affect alcohol-involved crime. This project will use detailed daily crime data across numerous U.S. jurisdictions to examine the relationship between police/community crime prevention events and alcohol- involved crime. Our analysis will address the following questions: 1) Do police-led community events reduce DUI, alcohol-involved crime, or other crimes? 2) How long do the crime-reducing effects of these events last? 3) Does the impact of community policing events vary according to the characteristics of the community or law enforcement agency? 4) What are the costs of crime avoided by effective community policing events? Theoretically it seems plausible that enhanced police-community engagement might allow police to more effectively prevent and investigate crime. However, existing empirical studies do not capture the causal effect of community policing on crime, nor do they permit practitioners to understand how a strategy such as convening police-led public events might contribute to an overall public health approach to reducing alcohol and drug-related crime and violence. Moreover, despite the fact that community policing events often include components designed to reduce substance misuse, work on the effects of community policing has focused on violent and Part I crime, with little attention given to alcohol or drug-related crime. This study seeks to measure the impacts of policing events by employing high-frequency data that specifically identifies incidents of alcohol and drug-related crime and domestic violence. It exploits variation arising from the National Night Out (NNO) program, during which police/community events are organized across thousands of communities and held each year on the same date. NNO events are held on a different date in Texas than in other U.S. states, furnishing an opportunity to measure the effects of community policing events using a differences-in-differences research design. In addition to providing more credible empirical estimates of the effects of police-led events, the study will demonstrate whether such events are more effective in certain types of communities or at addressing particular types of crime. This research will allow policymakers, police chiefs, and the public to better understand whether and how police-led crime prevention events can enhance public health by reducing alcohol-involved crime and violence. It will also allow stakeholders to better calculate the return on investment from organizing such community policing events.